Transformer Zs

[happysparks]

I've been doing some test on some 230/110v transformers and have no problems usually but over the last week I have come across 3 transformers that have given me good readings on the primary and secondary side of the transformer but when i'm doing the Zs on the secondary side I am getting values like 47v and 57v between phases and earth but am only getting 12v between phases. I've used 2 kinds of metrel tester and the Meggar MFT1730 but none of them will let me do the earth fault test does anyone have any ideas why this would be?

 

[infinity]

The testers will not earthloop test on 110V

and where would it be testing to? Its a transformer

 

[Adam]

Merger MFT's will test earth loops above 50 volts, and we are required to prove over current protection for 110v supplies.

http://www.megger.com/common/documents/MFT1700_DS_en_V05.pdf

 

[happysparks]

center tap. All test sheets have Zs for transformers mate.

The testers will not earthloop test on 110V

and where would it be testing to? Its a transformer

 

[Knobhead]

The testers will not earthloop test on 110V

and where would it be testing to? Its a transformer

I don't come in this section often but I was bored.

Here's a drawing now tell me why you can't test earth loop.

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